I believe that leader only weapons can be given to the rest of your gang as you please after recruitment. The leader only thing is just for when you first recruit your gang.
Automatically Appended Next Post: In fact, here's a quote from the rules:
page 78 wrote:Leader Only Weapons
When a gang is first created, certain weapons are
restricted to their leader, as noted in the weapon lists
opposite. After a campaign has begun however, these
weapons may be purchased for any gang member,
using the normal trading post rules.